Low frequency damping capacity in a strained Fe-Mn-Si alloy

The low frequency damping capacity of a strained Fe-31.36Mn-3.15Si (wt.%) alloy has been investigated using a multifunctional internal friction apparatus (MFIFA) through the free decay and forced vibration method. The high damping source is proposed to have originated from the irreversible movements of e/γ boundaries, being amplitude-dependent damping. An internal friction peak appears on the internal friction-temperature curves at about 280°C during heating from room temperature to 400 °C and the peak height is drastically reduced during subsequent in situ cooling. The peak height increases with increasing T/f. It has been suggested that the internal friction peak is resulted from the e → γ transformation during heating.